Mendix does not have the necessary permissions to access the specified path.
- Right-click on the folder .mendix-cache.
- Select "Properties."Go to the "Security" tab.
- Check the permissions for your user account and ensure that it has "Full control."
- If necessary, click "Edit" to modify the permissions and grant "Full control" to your user account.
You can also run the Mendix Studio as an administrator. Right-click on the application or the Mendix Studio Pro executable and select "Run as administrator."
The above solution didn't work, so instead navigate to Mendix folder, and delete the folder named 'App Name-branch'.
Close Mendix, and re-open. Now when you open the app, Mendix will create a new folder for that app and branch without issues.
(Bear in mind you may loose any unsaved changes)